The index graded personal computer satisfaction 80 out of 100. Tablet computers, along with desktops and laptops, gained 2 points over its score in 2011. The inclusion of tablets in the category, though controversial, was partly responsible for the improved ranking of PC satisfaction. The ACSI said that tablets were included with personal computers in the survey because respondents included tablet computers when they were asked whether they had bought a PC in the past three years.

The survey ranked customer satisfaction with particular PC vendors as well. Even though market share among consumers has decreased, approval of several vendors rose. Despite its decreasing computer shipments, Dell (NASDAQ:DELL) scored 79, a five percent increase over last year, and Hewlett-Packard’s (NYSE:HPQ) score increased one percent to 79.

Apple (NASDAQ:AAPL) topped the satisfaction list like last year, though its score dropped by a single percentage point. The ACSI, which interviews approximately 70,000 customers each year to measure satisfaction in more than 230 companies in 47 different industries, gave the company an 86 out of 100. The index attributed the lower score in part to inclusion of the iPad in the PC category, and in part to the success of PC vendors in “pleasing the customers that they are keeping.”

“What may be occurring is that the defection of the least satisfied customers of traditional PC brands such as Dell, HP, and Acer to Apple and other smaller tablet makers actually may be boosting customer satisfaction for all,” said ACSI founder Claes Fornell in a statement. “The companies that lose market share will maintain their most loyal and happy customers, while those who migrate to other companies in search of new products are more pleased as well.”